Using Electrical Conductivity and Total Dissolved Solids Meters to Field Test Water Quality

[@Gorgie-lm1ti]

Can I use my flute meter

[@philipbowman6415]

A 1/4 tsp of salt weighs about 1.5 grams, per google. 4 cups of water is essentially a Liter or so. So 1.5 grams in a liter would be 0.15%,right? Why is the correct value not 1500 ppm? What am I missing?